US2002051116A1PendingUtilityA1
Eye tracker for refractive surgery
Priority: Nov 6, 1998Filed: May 4, 2001Published: May 2, 2002
Est. expiryNov 6, 2018(expired)· nominal 20-yr term from priority
G06T 2207/30041A61F 2009/00872A61F 2009/00846G06T 7/73A61F 9/00804A61B 3/113G06V 40/193
28
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Claims
Abstract
A method of determining the position or attitude of an eye, including the steps of directing a plurality of eye-safe light beam components onto the eye, said components defining an area of incidence on the eye substantially larger than the pupil; receiving an image of light thereafter reflected by the eye; analyzing the image by identifying which of the light beam components produces a bright eye reflection in said image; and determining the position or attitude of the eye by further analysing the image on the basis of said identification.
Claims
exact text as granted — not AI-modified1 A method of determining the position of the pupil of an eye, including the steps of:
directing an eye-safe light beam having a plurality of components onto the eye, said components defining an area of incidence for the beam on the eye substantially larger than the pupil of the eye;
receiving an image of light thereafter reflected by the eye;
analysing the image by identifying which of the light beam components produces a bright eye reflection in said image;
determining the position of the pupil by further analysing image on the basis of said identification.
2 A method according to claim 1 wherein said eye-safe light beam defines a device comprising a pair of crossed lines that form said plurality of components.
3 A method according to claim 1 wherein said eye-safe light beam defines a grid of intersecting lines that form said plurality of components.
4 A method according to claim 1 wherein said eye-safe light beam is an array of light spots that form said plurality of components.
5 A method according to claim 1 further including generating said eye-safe light beam having a plurality of light beam components by splitting an initial light beam into said components.
6 A method according to claim 5 wherein said initial light beam and said light beam components are collimated.
7 A method according to claim 5 wherein said eye-safe light beam defines a device comprising a pair of crossed lines that form said plurality of components.
8 A method according to claim 5 wherein said eye-safe light beam is an array of light spots that form said plurality of components.
9 A method according to claim 1 wherein said further analysis is effected utilising image data for a calculation window centred on said identified component.
10 A method according to claim 9 wherein said eye-safe light beam defines a device comprising a pair of crossed lines that form said plurality of components.
11 A method according to claim 9 wherein said eye-safe light beam is an array of light spots that form said plurality of components.
12 A method according to claim 1 , further including:
directing at least one further eye-safe light beam onto said eye from a lateral direction; and
receiving a further dark-eye image of light thereafter formed by reflection of said further light beam(s) by the eye;
wherein said further analysis includes subtracting or otherwise comparing said images.
13 A method according to claim 8 wherein there are a plurality of said further beams directed from different lateral directions.
14 A method according to claim 1 further including recording said image(s).
15 A method according to claim 1 , including repeating said steps to monitor changes in the position of the pupil of said eye.
16 A method for controlling the aim of a surgical laser including determining the position of the pupil of an eye according to claim 1 , and further including controlling said aim in response to said determined position.
17 A method according to claim 16 wherein said eye-safe light beam defines a device comprising a pair of crossed lines that form said plurality of components.
18 A method according to claim 16 wherein said eye-safe light beam is an array of light spots that form said plurality of components.
19 A method according to claim 16 further including generating said eye-safe light beam having a plurality of light beam components by splitting an initial light beam into said components.
20 A method according to claim 16 , further including:
directing at least one further eye-safe light beam onto said eye from a lateral direction; and
receiving a further dark-eye image of light thereafter formed by reflection of said further light beam(s) by the eye;
wherein said further analysis includes subtracting or otherwise comparing said images.
21 A method according to claim 16 , including repeating said steps to monitor changes in the position of the pupil of said eye.
22 A method according to claim 1 wherein said eye-safe beam is a beam of infra-red light.
23 Apparatus for determining the position of the pupil of an eye, including:
means for directing an eye-safe light beam having a plurality of components onto an eye, said components defining an area of incidence for the beam on the eye substantially larger than the pupil of the eye;
means for receiving an image of light thereafter reflected by the eye;
means for analysing the image by identifying which of the light beam components produces a bright eye reflection in said image, and for further analysing the image on the basis of such identification, whereby to determine the position of the pupil.
24 Apparatus according to claim 23 , wherein said eye-safe light beam defines a device comprising a pair of crossed lines that form said plurality of components.
25 Apparatus according to claim 23 , wherein said eye-safe light beam defines a grid of intersecting lines that form said plurality of components.
26 Apparatus according to claim 23 , wherein said eye-safe light beam is an array of light spots that form said plurality of components.
27 Apparatus according to claim 23 including means for generating an eye-safe light beam and optical means for splitting the beam into said plurality of components.
28 Apparatus according to claim 27 wherein said light beam and said components are collimated.
29 Apparatus according to claim 27 , wherein said eye-safe light beam defines a device comprising a pair of crossed lines that form said plurality of components.
30 Apparatus according to claim 27 , wherein said eye-safe light beam is an array of light spots that form said plurality of components.
31 Apparatus according to claim 23 , further including:
means for directing at least one further eye-safe light beam onto said eye from a lateral direction, said image receiving means also being arranged to receive a further dark-eye image of light formed by reflection of said further beam(s) by the eye;
wherein said further analysis includes subtracting or otherwise comparing said images;
said analysing means also comparing said images as part of said further analysis.
32 Apparatus according to claim 31 wherein there are a plurality of said further beams directed from different lateral positions.
33 Apparatus according to claim 23 wherein said image receiving means includes means to record the image(s).
34 Apparatus according to claim 23 wherein said eye-safe light is infra-red light.
35 Surgical laser apparatus including laser means for producing a beam of ablative radiation and aiming the beam at an eye, and apparatus according to claim 23 for determining the position of the pupil of said eye and for controlling the aim of said beam of ablative radiation in response to said determined position.
36 Apparatus according to claim 35 , wherein said eye-safe light beam defines a device comprising a pair of crossed lines that form said plurality of components.
37 Apparatus according to claim 35 , wherein said eye-safe light beam is an array of light spots that form said plurality of components.
38 Apparatus according to claim 35 including means for generating an eye-safe light beam and optical means for splitting the beam into said plurality of components.
39 Apparatus according to claim 35 , further including:
means for directing at least one further eye-safe light beam onto said eye from a lateral direction, said image receiving means also being arranged to receive a further dark-eye image of light formed by reflection of said further beam(s) by the eye;
wherein said further analysis includes subtracting or otherwise comparing said images;
said analysing means also comparing said images as part of said further analysis.
40 Apparatus for facilitating determination of the position of the pupil of an eye, including:
means for generating an eye-safe light beam;
optical means disposed to receive said light beam for splitting it into a plurality of light beam components to be directed onto an eye, said components defining an area of incidence for the beam on the eye substantially larger than the pupil of the eye; and
means for receiving an image of light thereafter reflected by the eye;
wherein said light beam defines a device comprising one or more devices selected from a pair of crossed lines, a grid of intersecting lines, and an array of light spots that respectively form said plurality of components.
41 Apparatus according to claim 40 wherein said light beam and said components are collimated.
42 Apparatus according to claim 40 , further including:
means for directing at least one further eye-safe light beam onto said eye from a lateral direction, said image receiving means also being arranged to receive
a further dark-eye image of light reflected from the eye after incidence of said further light beam(s).
43 Apparatus according to claim 42 wherein there are a plurality of said further beams directed from different lateral positions.
44 Apparatus according to claim 40 wherein said image receiving means includes means to record the image(s).
45 Apparatus according to claim 40 wherein said eye-safe light is infra-red light.
46 Surgical laser apparatus including laser means for producing a beam of ablative radiation and aiming the beam at an eye, and apparatus according to claim 42 for facilitating determination of the position of the pupil of said eye and for controlling the aim of said beam of ablative radiation in response to said determined position.
47 Apparatus according to claim 46 , further including:
means for directing at least one further eye-safe light beam onto said eye from a lateral direction, said image receiving means also being arranged to receive a further dark-eye image of light reflected from the eye after incidence of said further light beam(s).
48 Apparatus according to claim 46 wherein said image receiving means includes means to record the image(s).
49 An apparatus for determining the position of the pupil of an eye during refractive surgery so that the aim of an ablative laser can be adjusted accordingly, including:
laser means for producing a beam of ablative radiation;
a first infra-red light source for illuminating the pupil of said eye;
an optical system for directing said first infra-red source;
a second infra-red light source for illuminating the iris of said eye;
focussing means for focussing light reflected from surfaces of the eye;
recording means for recording images of the light reflected from said surfaces;
image processing means for determining the position of the pupil of the eye; and
controller means for directing said laser to the appropriate position on the cornea in accordance with the determined position of the pupil.
50 Apparatus according to claim 49 wherein said first infra-red light source is a collimated light source.
51 A method for determining the position of the pupil of an eye during ablative laser surgery so that the aim of the ablative laser can be adjusted accordingly, including:
directing a first beam of infra-red light from a first position onto said eye;
directing at least one second beam of infra-red light from a second position onto said eye through an optical system;
imaging light from said first and second beams reflected from said eye to form first and second images respectively; and
comparing said images to determine said position of the pupil of said eye.Join the waitlist — get patent alerts
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